In the industry, folding boxes are traditionally manufactured by folding and gluing of blanks which have previously been formed from sheets of cardboard. Forming in this way generally consists in pre-cutting the sheets in question individually, discharging the waste, then separating the blanks which constitute each sheet, while proceeding progressively to stack these blanks for the purpose of making them easy to use in a folding and gluing machine. The step of separation of blanks conventionally consists in breaking the points of attachment which connect the blanks, by means of the combined action of a male upper tool and a female lower tool which are specific to the work to be carried out.
In order to guarantee the stability of the different stacks of blanks at the end of the forming process, it is known to proceed with periodic insertion of a separation sheet during the final stacking, by inserting a separation sheet each time a certain number of blanks has been stacked. In order for this insertion to be carried out without needing complete stoppage of the converting machine, use is habitually made of a temporary receipt device which is commonly known as a non-stop grid or rack.
A typical non-stop rack in the art consists schematically of a mobile carriage on which a plurality of parallel bars are mounted. These parallel bars are arranged longitudinally inside the converting machine, in order to form a type of rack which can penetrate the fixed tool for separation of blanks, but can also receive the blanks. Each bar is also mounted on the carriage such as to be able to be withdrawn or repositioned transversely according to the profile of the fixed tool for separation of blanks. The carriage, for its part, is mounted such as to be mobile in longitudinal displacement within the converting machine, according to a movement of alternating translation. The assembly is designed such that this mobility is exerted between a receipt position, in which the bars can support temporarily the blanks which are being stacked, and a released position, in which the said bars are placed spaced from any stack.
However, this type of non-stop rack has the disadvantage that it is relatively problematic to adjust. In fact, each bar repositioning, which consists in unlocking in the initial position, then displacement to the final position, before locking once more once the said final position has been reached, must be carried out both manually and individually. However, the implantation of the non-stop rack at the heart itself of the converting machine makes the bars difficult to access, which inevitably complicates any manual intervention by the operator. The fact that each non-stop bar must be repositioned individually tends, for its part, to increase the number of the operations of unlocking, displacement and locking, and therefore to generate adjustment times which are particularly long. Finally, it is complicated to obtain optimum precision of adjustment, taking into account the lack of visibility of the bars, caused by the implantation of the non-stop rack inside the converting machine.
Thus, a technical problem to be solved relates to provision of a non-stop rack device for temporary receipt of the flat elements in the form of sheets in a converting machine, the said device comprising a plurality of parallel bars which are integral with a mobile support which can be displaced between a receipt position, in which the bars can support temporarily the flat elements which are being stacked, and a released position, in which the said bars are placed spaced from any stack of flat elements, which device would make it possible to avoid the problems which exist in the art, by providing in particular adjustment which is substantially facilitated.